1.1 本规范 2. 涵盖用于焊接压力容器和管道部件的高强度低合金钢板。 1.2 这种材料特别适用于需要高强度和改善韧性的管道和压力容器应用。 1.3 本规范涵盖了B和C两个等级。B级的最小屈服强度为50ksi[345MPa]。C级的最小屈服强度为60ksi[415MPa]。 1.4 板材的最大厚度仅受化学成分和热处理能力的限制，以满足规定的机械性能要求；然而，目前的做法通常将每个等级的最大厚度限制在4英寸[100毫米]。 1.5 轧制状态下的C级在火焰切割、运输和搬运过程中容易开裂，特别是厚度超过2英寸[50毫米]时。除非制造商和买方双方同意，否则钢板不应仅以轧制状态装运。 1.6 以英寸-磅单位或国际单位表示的值应单独视为标准值。在文本中，国际单位制显示在括号中。每个系统中所述的值不是完全等效的；因此，每个系统都必须独立使用。结合两个系统的值可能会导致不符合规范。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。

1.1 This specification 2 covers high-strength low-alloy steel plates for service in welded pressure vessels and piping components. 1.2 This material is particularly intended for piping and pressure vessel applications where high strength and improved toughness are required. 1.3 Two grades, designated B and C, are covered by this specification. Grade B provides a minimum yield strength of 50 ksi [345 MPa]. Grade C provides a minimum yield strength of 60 ksi [415 MPa]. 1.4 The maximum thickness of plates is limited only by the capacity of the chemical composition and heat treatment to meet the specified mechanical property requirements; however, current practice normally limits the maximum thickness to 4 in. [100 mm] for each grade. 1.5 Grade C in the as-rolled condition is sensitive to cracking during flame cutting, transit, and handling, particularly in thicknesses over 2 in. [50 mm]. Plates should not be shipped in the as-rolled condition only except by mutual agreement between the manufacturer and the purchaser. 1.6 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.